Process of manufacturing imitation leather



Dec. 4, 1928. 1,694,258

R. c. HA RTQNG PROCESS OF MANUFACTURING IMITATION LEATHER Filed May 24, 1923 AA A ATTOBN w Patented cc. 4, 192.

UIT

ROBERT CTIFFORD HARTONG, OF AKRON,

OHIO, ASSIGNOB. TO SEII BERLING- RUBBER COMPANY, OF AKRON, OHIO, A CORPORATION OF DELAWARE.

PROCESS OF MANUFACTURING IMITATION LEATHER.

Application filed May 24,

- ton sheeting, with a plastic water-proof material, but preferably with a rubber composition in the manner as hereinafter set forth,

wherein a plurality of coats or layers of varying composition are applied by well known methods to a textile fabric and the rubber product vulcanized My invention further consists in an imitation leather possessing a very smooth, shiny surface, much resembling, but superior to the varnished (or lacquered) surface of patent leather, in that my product, being prepared of plastic and flexible materials, does not crack and break away from the surface during wearing as do thepatent leather 2 surfaces. It is possible, furthermore, to pass my material over embossing or graining rolls, and obtain a product carrying a raised or em bossed surface, or one grained in imitation of grain leather.

It is also an object of my invention to pro duce a smooth, glossy surface on a textile fabric, friction-coated or impregnated with a compound of a plastic nature, by first apply:

ing the plasticized material or compound to a metallic. liner and then removing the compound from the liner in a manner as herein after set forth, whereby said liner transfers its own surface effects to the-rubber composition attached thereto. This liner may be made of tin, aluminium, tinned-iron, or other surface treated iron, or may be an alloy, or in fact, any other metal or; combination of metals, which do not-form sulfides readily. It is, then, an object of my invention, to producea product possessing a smooth, glossy surface by methods differing from those .in

Y common use, and to obtain this desirable and satisfactory surface appearance without the use of expensive molds, plates, hydraulic ouring presses, or other cumbersome and expensive equipment in common; use, thereby reducing the cost of equipmentneeded, and the amount of laborneededto manufacture the material. I

In practicing this improved process, I pre- 1923. Serial No. 641,258.

pare a compound containing rubber and other ingredients, as set forth hereinafter in detail, and then calender or coatthis com pound, which I Wlll designate as compound A upon a metallic sheet, in the formof a metallicflliner, by ordinary calendering practice. In order to give this compound A the proper backing, a textile, such as cotton sheeting, can be frictioned with a rubbercontaining compound, hereinafter designated as compound B. This textile containlng compound B, is then doubled upon compound A, which, as was pointed out, has has been previously calendered upon the metallic sheet or liner. By the term doubling, refer to that process or step well known in the art of preparing a treated fab-- ric whereby a fabric coated on one side with a layer of waterproof material is folded upon or laid against a second layer of waterproof material which in its turn may or may not have a fabric backing. That is two surfaces of waterproofing'material, at least one of which has, a suitable fabric backing, are folded or laid upon one another preferably by means of sufficientpressure usually applied by the calendering rolls to ensure a firm union between the waterproofing surfaces. This combination may then be tightly wrapped upon a cylindrical drum to the extent of several hundred yards in one continuous length, and the edgesof the product I tightly wrapped with curing aprons or wraps, as is commonly practiced in curi n'g rubber sheet on drums, to protect the product from the bad effects ofsteam during the vulcanization process. WVhen prepared in this. manner, the product on the drum is cured in an ordinary open heat steam vulcanizenor by any other well known method of curing rubber compounds by heat. After vulcanization, the product is unwrapped, and removed from the drum by means of any ordinary and well known method.

My. preferred .process of preparing. the various compounds mentioned herein and my final product may be readily understood by reference to the drawings in which Figure 1 is a diagrammaticrepresentation of a means of preparing the various compounds, Figure 2 is a diagrammatic representation of a' means of preparing my final product and Figure 3 is a sectional view through the final product. Referring to Figure 1, the rollsyof a calendering machine,

l It, R R are turning in the directions indicated by the arrows. Rubber or a suitable rubber composition 6, for example compound A, previously plasticized'and mixed on the differential rubber mills, is positioned as indicated before the two upper rolls, R, B.

A metallic liner 8, on a roll R turning as indicated and guided by guide roll 9, is passed between rolls R R of the calendering machine and has laid thereon a layer 7 of the rubber composition 6. The calendered product 10 comprising a metallic liner carrying on one side a composition hereinafter referred to as compound A,is then wound upon roll R. Using the same equipment and the same process as just described but substituting a roll of textile fabric for the metallic liner before mentioned, the fabric may be coated with compound B. This coating may be placed first on one side and then if desired, by reversing the roll of treated fabric, and running it through the calendering machine as before described, a coating of the sameor of a different composition may be applied to the opposite side of the fabric.

Referring to Figure the metallic liner and turning in the direction indicated, is doubled upon the compound B calendered upon the fabric and positioned on roll R by passing the materials between the rolls R R of acalendering machine and winding the doubled product on the, roll R as shown. This product may then be wrapped hereinafter described. As previously mentioned the metallic liner may be smooth or embossed with any design desired, and during the vulcanization process, the surface effects of'the liner are transferred to the rubber composition -in contact therewith. Afterthe vulcanization step is finished, the product is unwrapped and then unrolled and the metallic liner removed. 7 The product is then ready for use in any manner as desired.

This product, as shown in Figure-3, comprises a textile fabric 3, calendered upon one side with a plastic composition 2 (compound a B) which is doubled upon another plastic composition 1 (compound A), said textile fabric 3 being also calendered upon its opposite side with a plastic composition 4 (compound C) said composition 4 containing fibers as described. 'After buffing, a nap N is raised over the surface of this compound. Inasmuch as the composition 1 (compound A) is preliminarily laid as described upon a metallic liner, the surface effects of the liner are transferred tothe composition 1 topro duce an imitationpatent leather surface In case the liner is embosseda similar effect-is produced on the surface S.

Altho the nature of the rubber compound used is not an essential part of my invention, the following composition is given as illus- 2 ofthe drawings, a -roll R carrying compound A calendered on and vulcanized inthe manner as ,equivalent material.

S. ing therein,

.of cotton seed oil and trative of one which serves very satisfactorily as the compound to be calendered on to the metallic liner, and referred to above as compound A. mixed on the difi'erentiaL mixing mills, parts of rubber, 10 parts of gas black,l5 parts of sulfur, 10 parts of mineral rubber, 2 parts of the acetaldehyde derivatives of the polymerized ethylidene aniline (an accelerator known to the rubber trade as A-7') part I of paraffin, 2 parts of cottonseed oil, and one part of Cycline oil (a compounded mixture of vegetable oil and mineral oil). Compound B, which, as was mentioned above, is frictionedon the textile material, and then doubled on compound A, preferably has as its composition, 84 parts of rubber, 10 parts of glue, parts of sulfur, part of thiocarbani'lid, 3 parts of cottonseed oil, an'd .2 parts of Gycline oil. The methods of mixing the quantities of, or even substitutions for, the ingredientsthemselves are apparent to those skilled in the art of rubber compounding. These formulae are, however, illustrative of a type of compound that has proved to be very successful in the practice of my invention. The time of cure necessary for vul; canizing these materials, varies according to the number of plies on the curing drum. For example, a roll or drum, wrapped as de- For this compound, there are these materials, as well as Variations in scribed, and containing about yards of my treated fabric, requires approximately 3 and hours heating at 30 pounds steam pressure, with about 30 minutes additional in the heater with the steam turned off to insure more uniform heat distribution.

The appearance and usefulness of the product prepared in the manner just disclosed, can be improved by calendering the textile material, referably of cotton fabric, as was hereinbe ore mentioned, on the side opposite the side carryingthe compound A. This calendering operation is done by the ordinary skim coating method of calendering, and consists in simply spreading a thin film of a composition (referred to hereinafter as compound C), rendered plastic in the usual manner, onto a backing, preferably of fabric, or other The following rubber composition is given as illustrative of the type I prefer to use for the calenderingprocess just described. This compositiom referred to inmy description as compound 0, is prepared in the usual manner, by breaking down, or plasticizing, on the differential rubber mixing rolls, parts of rubber, preferably of the gradeknown as plantation rubber, and then adding and homogeneously incorporat- 135 parts of cotton linters, 20 parts of glue, 20 parts of zinc oxide, 70 parts of lithopone, 4 and parts of sulfur, 2 parts of paraflin, 2 parts of phenanthrene, part part of thiocarbanilid. The actual methods of mixing this surface, resembling suede leather.

compound and of calendering it onto the cotton fabric, are so well known to those skilled in the art, that no further description of the actual process is necessary.

It is apparent, then, that I have prepared a product comprising a textile base, one side of which is skim-coated with compound C, while the opposite side is friction-coated with compound B, said Compound B being doubled upon Compound A,,which has itself been previously calendered upon a metallic sheet'or liner. The subsequent steps offinishing the product are the same as were mentioned before,that is, the finished material is wrapped on a drum, the ends covered with curing aprons, and the product then cured in an open heat steam vulcanizer for the required period of time. After unwrapping the vulcanized product, the side carrying compound C is preferably buffed with emery cloth, carborundum cloth, or any abrasive material, or treated by any other process which will raise the nap in the compound C. In this manner a surface is realized which has all the appearance, as well as the necessary physical properties of, a suede leather. It is obvious, then, that this final product consists of a textile bas3, so treated with rubbercompositions that one'side has a smooth glossy coating resembling patent leather, while the opposite side has a fibrous, nappy This synthetic product has numerous advantages over all previously known artificial products of the nature of leather.

The natural leather finish which is much to be desired in compounds of this type, can be even more closely imitated by using a metallic liner which can be embossed in the well known manner upon an embossing calender. The process for making the product having an embossed surface is similar to the process already described, except that the metallic liner used has an embossed surface,

' which transfers its surface effect to the rubber composition calendered thereon. The composition calendered issufiiciently stiff and firm to 'retain any markings impressed by the embossed liner, while pressure applied in the wrapping on. the drum for the vulcanizing step is not great enough to have any detrimental effect on the design transferred to the plastic composition. In order to ob.- tain the best results, itis desirable, when calendering compound- A on this liner, to use an idler roll which is cloth covered. By means of this roll, compound A, after it has been calendered, so that it will flow properly into, and thereby completelyfill the embossed surface'pfthe metallic liner, in order reproduction of the pattern desired. This embossed composition can now be used'in building up the artificial leather com ound, according to the manner already descr1bed,-

. ply stock of compound D pressure is applied to y to obtain a complete that is, it has doubled upon it a textile base,

friction coated with a compound B, and a the whole wrapped on a drum and cured.

Although. the imitation patent leather finish, prepared by the process as set forth is very durable, I .have found that its .wear-' resisting qualities can be increased by a slight modification in the process. The textile base, already coated or calendered on one side with compound B, may be plycoated or calendered over this compound with a composition which I designate as compound D, and which comprises 7 3 parts of rubber, 10 parts of glue, 4 parts of mineral rubber, 10, parts of gas black, 4 parts of refined uncured auto friction stock, 1 part of cotton seed oil, and part of sulfur. The milling of this composition, and the calendering of it onto the textile base, are carried out by the usual methods. After compound C has been applied to the opposite side of the fabric, and-compound A has been doubled, in the manner as described, upon theside of the product carrying compounds B and D, the product is vulcanized. In

this way I have prepared an artificial leather comprising a textile base, calendered on one side with compound C, and on the opposite side with compound a ply-coat of compound D, which is then doubled up on compound A, previously calendered, and preferably, but not necessarily embossed upon the metallic liner. The whole is then vulcanized. By the use of this interposed in my B, together with material between compound B and compound A, the aging properties and resistance to cracking of compound A are very appreciably improved. This improvement is brought about by the employment of compound D, which furnishes a tough and non-cracking under-coating or base for com pound A. Moreover, since compound D contains such a small percentage of free sulfur, its use further improves compound A, since there is probably a certain amount of sulfur migration from compound A into compound D during the vulcanization process. Since this migration would afiect the aging properties of the material, this would cause the inner portion of compound A to be more flexible, and noncracking than theouter portion, or the imitation patent leather surface. 1 At the same time, use of this ply-coated calendered compound D, does,

not disturb the harder surface cure of cornpound A, which gives to the material 1ts characteristic leather like properties. Compound A has in itself, very high resistance to cracking or to the efiects of aging for the reason that while the degree of vulcanization is cpmparatively high, the flexibility of the product is maintained by the use ofv the combination of the'oilsg'used in the com ound. Its desirable qualities are, however, urther int . tain proportions,

that my invention is enhanced by the use of the compound D,

applied as a ply coating over compound B as described.

Although in the examples set forth, I have specified the use claims appended hereto and made a part of calendered upon a metallic liner,

- rubber composition tion, doubling said this application and in which I intend to claim all novelty inherent in my invention which is permissible in view of the prior-art.

What I claim is 1. A process of manufacturing an imitation leather, which comprises frictioning a plastic composition on a textile fabric, doubling said fri'ctioned fabric upon a plastic composition previously calendered upon a metallic liner, and heat-treating the product.

2. A process of manufacturing an imitation leather,

hich comprises frictioning a on a textile fabric, doubling said frictioned fabric upon a rubber composition previously calendered upon a metallic liner, and vulcanizing' the product.

3..A process of manufacturing an imitation patent leather, which comprises calendering a rubber composition upon a smooth surface, capable of transferring its surface effects to said composition, doubling upon said composition a textile fabric frictioned with a rubber composition, the product. I

4. A process .of manufacturing an imita tion leather, which comprises frictioning a textile fabric on one side with a rubber composition, skim-coating said fabric on the side opposite said friction-coated side, with a rubber composition, doubling the friction coated side upon a rubber composition previously and vulcanizing the product. a

5. A ro cess ofmaki'ng an embossed imitav,tion leather, which comprises friction-coating a textile fabric with a rubber composifriction-coated' fabric upon a rubber coniposition previously calendered upon an embossed metallic liner, and vulcanizingth'e product.

6. A method of producing a surface efiect on a rubber. composition, which comprises I vulcanizing the product.

leather comprising a tex-.

foundation fabric and vu'lcanizing calendering said rubber composition upon a metallic liner.

7. A method of producing a smooth surface effect on a plastic composition, which comprises'calendering said plastic composition upon a metallic liner.

8., A method of producing an embossed sur; face on rubberized fabric, friotioning a rubber composition upon a textile fabric, doubling said frictioned fabric upon a rubber composition previously calendered upon an embossing calender, and

9. An imitation tile fabric base, friction coated on both sides with a plastic composition, one side of said coated fabric being united to a rubber composition bearing an embossed surface, the 0ppo'site side of said coated fabric being united to a rubber composition carrying fibers.

10. An imitation patent leather comprising a textile fabric base, friction coated with a rubber composition, one side of said coated fabric being united to a rubber composition possessing a glossy surface.

11. An imitation leather comprising a friction coated on one side with a rubber composition containing fibers and friction coated on the opposite side with a second rubber composition having an embossed surface.

12. An imitation leather product consisting of rubber compositions applied to a fabric base, one side of said product being finished as an imitation patent leather, and the opposite side being finished as an imitation suede leather. j

13,111 the manufacture of an imitation leather, the process comprising calendering a textile fabric with a rubber composition, ply coating'a rubber composition over said 7 calendered fabric, calendering a rubber com-' position 'upon a'metallic liner and doubling said compositionsone upon the other.

14. An embossed imitation leather comprising v a foundation fabric friction coated with a rubber-containing composition, said composition carrying a coating of arubber designs embossed therecomposition having on by an embossing calender.

ROBERT CLIFFORD HARTONG which consists in 

